January 10, 2013 FDC meeting
- Production Construction Tracking
- Corrosion tests (Lubomir)
- Electronics (Chris, Nick)
- Tests at EEL126 (Lubomir, Beni)
Participants: Eugene, Dave, Chris, Nick, Simon, Beni, and Lubomir.
- Dave: all components for the second (last production) package are ready. Redundant components: type-1 cathode #71 ready, working on three more cathodes. Starting next week Tina will work for BCAL, but will be available from time to time so that we can finish the rest of the cathodes. Casey finished with the lamination of wire frame #31 and now is gluing #32 (the last one). Anatoly is installing the caps on #31.
- How many redundant cells we want to make: according to the schedule 4, but most likely we have parts for 6. According to Dave we will need 5 more man-weeks to make four additional cathodes. As for the wire planes we anticipated having 7 of them, three of which with high dark current ~1 uA but stable, that probably can be fixed. Eugene agreed to build 6 spare cells.
- Lubomir: testing the first three cells of package #2. Cell #6 and #5 were checked so far: all channels working fine. Applying +2100/-500V, on #6 dark current <100nA. On #5 initially the current was not stable 200-600nA, but after leaving it at +2250/-500V over the night now it is stable (170nA at 2100V). By tomorrow cell #4 will be tested as well and we can continue with the stacking.
- Bases of Estimate for the FDC activities: we need to come with such estimations for the FDC activities as summarized in the spreadsheet attached; guidelines also attached above. Eugene: the idea is to understand what is the source of the estimations (both procurements and labor) for each activity and assign contingency accordingly. However, we should try to do the best estimates as of now (not at the time the last schedule was prepared) which may result in different numbers than what's in the schedule? This should be done for all the activities that are not finished yet as of now, not by the time on the next review (March/April). Lubomir and Dave will do the estimations for the cell production and package final assembly and testing. Lubomir will talk to Bill on Monday about the fiducial, cooling stuff and package assembly. Dave will make an estimate for the consumables needed till August. In addition it turned out we have to do that same for the FDC installation activities, which can be done with the Tim's/Tom's help.
Cathode corrosion test
- Lubomir: now we are certain that all the samples of test #1 failed because of the soldering; Vlad send photos of the samples to make sure we are re-measuring the right samples. Conclusion: the only case we had corrosion problem is at 100degC at 100% humidity: EPDM failed after 12 days. From all the tests (assuming same activation energy) we get a lower limit at room temperature of 1.5 years when using Viton+Apiezon.
- Vlad is planning to do corrosion tests in Moscow. The idea is to have a big container with water, keeping it boiling, and put another container inside with the samples. Vlad will make as many samples as possible to have better statistics. The problem again is how to do the soldering, probably applying Apiezon on the soldering place will help.
Tests at EEL126
- Fourth package was moved to 126 on Monday and flushed with 40/60 Ar/CO2 at 200sccpm since then. The problem was that the MKS system failed every night and in the mornings the pressure in the package was about 10-20Pa. Since yesterday, however, gas system seams stable. Chris and Nick finished the HV connections. Dave will put connectors on the return/shield cables, so we can start applying HV tomorrow.
- Beni is putting together the DAQ system, two fADC125 were with Cody, now back at 126 working OK with the old firmware. After the meeting Beni informed that the tests with the new fADC125, working with a new firmware that Cody implemented, were also successful! We discussed also changes in the DAQ code to do the charge summing before write the data to file. At present we write all the fADC samples which occupies a lot of space and slows the analyses. Beni answering Eugene's question: it will take a week to test one package after it is conditioned and assuming there are no problems. Eugene: in this case we should go ahead and do these partial test for all the packages.